Dear Linux kernel code maintainer,
some weeks ago in the course of a discussion on lkml
(see http://www.uwsg.indiana.edu/hypermail/linux/kernel/0110.3/1553.html
and follow-ups) linux kernels of the 2.4 series turned out to sometime
lock up after 497.1 days of uptime, when the "jiffies" variable wraps
back to zero.
Checking the kernel code, I found a number of places where jiffies
were compared in a way that seems to break when they wrap. For these,
I made up patches to use the macros "time_before()" or "time_after()"
that are supposed to handle wraparound correctly.
For a small part of the patches, I believe you to be the relevant kernel code
maintainer. Appended to this email you will find some lines explaining
why I decided to mail or cc: you on this (an extract of the copyright notice
or the MAINTAINERS file), followed by the patch itself. If I mailed you
in error, please drop me a short note.
I kindly ask you to approve the correctness of the patch, and pass it on to
the relevant people for inclusion into the mainline kernel.
Thanks,
Tim Schmielau (tim@physik3.uni-rostock.de)
MIPS
P: Ralf Baechle
M: ralf@gnu.org
W: http://oss.sgi.com/mips/mips-howto.html
L: linux-mips@oss.sgi.com
S: Maintained
--- linux-2.4.18-pre1/arch/mips/baget/vacserial.c Sun Sep 9 19:43:01 2001
+++ linux-2.4.18-pre1-jiffies64/arch/mips/baget/vacserial.c Fri Dec 28
14:57:14 2001
@@ -1785,7 +1785,7 @@
schedule_timeout(char_time);
if (signal_pending(current))
break;
- if (timeout && ((orig_jiffies + timeout) < jiffies))
+ if (timeout && time_after(jiffies, orig_jiffies + timeout))
break;
}
current->state = TASK_RUNNING;